What is the ruling on fasting the first day of Ramadan with intermittent bleeding, and is it obligatory to complete the fast on the second day after the bleeding stops?

Many scholars have opined that purification during menstruation is a valid purification, and during it, a woman must observe the rulings for pure women. She should perform ghusl (ritual bath), pray, and fast. So, if she sees purification at night, performs ghusl, and fasts, and the menstrual blood does not return during the day, her fast is valid. However, if the blood returns at any point during the day, she must make up that day.